customizing paypal checkout, including php variable - php

Question

I'm trying to add a "custom" value to the 3rd party checkout PayPal option. The problem I'm having is the PHP variable is being displayed on the screen. I'm passing the shopping cart values in a session variable.
if(isset($_SESSION['checkout'])){
$orderData = '<table border="1"><th style="width:80px">Item</th>
<th sytle="width:250px">Size</th>
<th style="width:60px">Quantity</th>';
for ($i=0; $i<count($_SESSION['checkout']); $i++){
$orderData .= '<tr><td style="text-align:center">'.$_SESSION['checkout'][$i][0].'</td><td style="text-align:center">'.$_SESSION['checkout'][$i][1].'</td><td style="text-align:center">'.$_SESSION['checkout'][$i][2].'</td></tr>';
}
}
I want that table to be passed along, and based on the PayPal documentation, all I need to do is include it. I'm echoing out the PayPal form like this:
echo '<form>
//other hidden values
<input type="hidden" name="custom" value="'.$orderData.'">
//input submit button here
</form>
And like I said, the input is supposed to be hidden, but it gets displayed before the PayPal button. How come?
UPDATE: Those code passes the amount perfectly:
<input type="hidden" name="amount" value="';?><?php if(isset($_SESSION['disc'])){print_r($_SESSION['disc']);}?><?php echo '">
It doesn't display on the page but the variable amount is correct in the page source.
UPDATE2: Here's my entire cart script:
echo '<div style="position:absolute; left:770px; top:50px">
<form action="https://www.paypal.com/cgi-bin/webscr" method="post">
<input type="hidden" name="cmd" value="_xclick">
<input type="hidden" name="business" value="myemail#example.com">
<input type="hidden" name="item_name" value="Merchandise">
<input type="hidden" name="currency_code" value="USD">
<input type="hidden" name="no_shipping" value="0">
<input type="hidden" name="custom" value="'.$orderData.'">
<input type="hidden" name="return" value="backtomywebsite.com">
<input type="hidden" name="cancel_return" value="backtomywebsite.com">
<input type="hidden" name="amount" value="';?><?php if(isset($_SESSION[$disc])){print_r($_SESSION[$disc]);}?><?php echo '">
<input type="image" src="http://www.mywebsite.com/images/BuyNow.png" name="submit" alt="Make payments with PayPal - it\'s fast, free and secure!" width="300" height="204">
</form>
</div>';
The script works when instead of $orderData I have a print_r session with the item information. That information gets sent to my paypal account but it is in an array form and looks ugly. If there was a way to make everything (member information, order information) into a php variable and pass it into the custom field, that would be great. Anyway...here's what is on the screen:
Hope you're still willing to help me out.

Answer 1

What do you mean it gets displayed before the PayPal button? If you are viewing the source code of the page, you will see the value in the page.
If you are saying you are passing amount over, but are not seeing it you may be using the wrong variable. The variable amount is a valid PayPal variable but depending what button you are specifically using the amount varialbe is slightly different. I could not tell from your code as I didn't see what you were passing over for "cmd", but if you are using a buy now button or an add to cart button that the variable "amount" would be the correct variable to use. If you are usnig the cart upload method, then you want to use the variable "amount_x". So if I passed two items over, and the first one was 0.99 and the second was 1.99 I would pass over the variable/value of "amount_1=0.99" and "amount_2=1.99".